Before the War he took over the fanzineNovae Terrae and renamed it New Worlds. After four issues he attempted to turn it into a prozine, but failed because the publisher he was working with turned out to be a crook.

After the War, he was successfully founder and first editor of a New Worlds prozine. He also edited Science Fantasy starting in the 1950s and then started the long-lived New Writings in Science Fiction anthology series.